title: Understanding adhesion at as-deposited interfaces from ab initio thermodynamics of deposition growth: thin-film alumina on titanium carbide.
abstract: We investigate the chemical composition and adhesion of chemical vapour deposited thin-film alumina on TiC using and extending a recently proposed nonequilibrium method of ab initio thermodynamics of deposition growth (AIT-DG) (Rohrer and Hyldgaard 2010 Phys. Rev. B 82 045415). A previous study of this system (Rohrer et al 2010 J. Phys.: Condens. Matter 22 015004) found that use of equilibrium thermodynamics leads to predictions of a non-binding TiC/alumina interface, despite its industrial use as a wear-resistant coating. This discrepancy between equilibrium theory and experiment is resolved by the AIT-DG method which predicts interfaces with strong adhesion. The AIT-DG method combines density functional theory calculations, rate-equation modelling of the pressure evolution of the deposition environment and thermochemical data. The AIT-DG method was previously used to predict prevalent terminations of growing or as-deposited surfaces of binary materials. Here we extend the method to predict surface and interface compositions of growing or as-deposited thin films on a substrate and find that inclusion of the nonequilibrium deposition environment has important implications for the nature of buried interfaces.
authors.affiliation: BioNano Systems Laboratory, Department of Microtechnology, MC2, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden. rohrer@chalmers.se
authors.forename: Jochen
authors.initials: J
authors.lastname: Rohrer
authors.forename: Per
authors.initials: P
authors.lastname: Hyldgaard
mesh_terms: D000268:Adhesiveness; D000537:Aluminum Oxide / Q000737:chemistry*; D003198:Computer Simulation; D008567:Membranes, Artificial; D008956:Models, Chemical; D013499:Surface Properties; D013816:Thermodynamics; D014025:Titanium / Q000737:chemistry*
chemical_list: D008567:Membranes, Artificial; C096521:titanium carbide; D014025:Titanium; D000537:Aluminum Oxide